Rail anchor and method of making same



July 6, 1965 E. L. GROFF ETAL SSS RAIL ANCHOR AND METHOD' OF MAKING SAME4Filed Nov. 14, 1965 United States Patent Oiiice 3,l93,2dl Patented July6, 1965 3,193,201 RAIL ANCHOR` AND METHD F MAKING SAME Emory L. Groff,Bethesda, and Charles T. Walker, Rochville, Md., assignors to Poor &Company, Chicago, lll., a corporation of Delaware Filed Nov. 14, 1963,Ser. No. 323,677 6 Claims. (Ci. 23S-331i) This invention relates to aone-piece rail anchor and more particularly to a rail anchor of plasticmaterial and to the method of making same.

Rail anchors comprising a single steel element provided with an openhook or jaw portion adapted to grip the base ilange of a railroad railare well known, this form being the most common ltype of anchor used byrailroads throughout the World.

Heretofore, all such rail anchors have been constructed of metal,usually a low or medium carbon mild steel, since this was the only knowneconomical material which possessed the required strength to meet thedemands imposed upon such devices, it being readily apparent that asteel anchor, properly fabricated, would inherently possess the tensilestrength required in the area of the jaw to sufliciently grip the baseange of the rail to prevent creeping of the rail in a direction normalto the axis of the cross tie.

Significant advancements have been made in recent years in theformulation of synthetic plastic resin compounds possessing extremelyhigh structural properties. Perhaps the most usual application involvingthese compounds is in the iield of structural adhesives whereincountless plastic resins have been developed which may be used to joinmaterials and provide a bond having even a greater resistance tospecific stresses than the material itself.

Until now, no one has been able to develop a rail anchor of plasticcomposition since it has been impossible to achieve sufficient strengthin the required areas by merely molding an anchor of plastic materialalone, even in view of the newly developed high strength syntheticresins.

However, the present invention for the tirst time, so far as we areaware, provides for the formation of a plastic rail anchor having areinforcing filler arranged in such a manner as to provide an articlehaving a tensile strength in the required areas commensurate with thatof the steel anchor. The advantages attendant to such an advancement inthe art are numerous, the most irnportant of which are the economicalaspects. In the case of steel anchors, it is necessary to provide andmaintain rolls, shears, ovens, dies and tools as Well as other heavyequipment, all operated by high-wage personnel, while only a fraction ofthis etort is required for manufacturing the present plastic anchor.Steel anchors are usually produced in single units while the plasticanchor of the present invention may be manufactured on machinesaccommodating ten or more anchors at a time.

Moreover, the cost of storing and shipping is far less for the plasticanchor which weighs approximately onefourth the amount of the steelanchor. The shipping cost factor cannot be underestimated in thisconnection, because the manufacture of rail anchors is a relativelyspecialized iield and a manufacturer usually maintains but a singleplant from which the anchors are shipped to railroads all over thiscountry, as well as to railroads throughout the world.

An important use for a rail anchor of plastic would be in connectionwith the recently introduced electronically controlled rail systemwherein, a single operator sitting at a control panel, automaticallycontrols several unmanned trains operating over a single rail net, forexample between two distant points in an iron ore mine complex. In sucha system, electrical impulses are transmitted through the rails tocontrol the ditierent locomotive engines at several diiierent speeds andto regulate the braking controls. The use of steel rail anchors wouldinterfere with the maintenance of the critical elec tronic circuitsbeing transmitted through the rails, contrary to the plastic anchorwhich is a non-conductive, nonmagnetic, and non-corrosive element.

Accordingly, a primary object of this invention is to provide a railanchor constructed of synthetic plastic resin.

Another object of the invention is to provide a reinforced plastic railanchor having a filler material arranged to provide maximum tensilestrength in specified areas. Still another object of this invention isto provide a method for manufacturing rail anchors of plastic material.A urter object of this invention is the provision of a method for themanufacture of plastic rail anchors having a reinforcing ller material.

With these and other objects in view which will more readily appear asthe nature of the invention is better understood, the invention consistsin the novel construction, combination, and arrangement of parts,hereinafter more fully described, illustrated, and claimed.

A preferred and practical embodiment of the invention is .shown in theaccompanying drawing, in which:

FIG. l is a perspective view of one form of a plastic rail anchor of thetie bearing type produced according to the invention.

FIG. 2 is a side elevation showing the rail anchor of FIG. l, as appliedto a rail and in abutment with a cross tie.

FIG. 3 is a side elevation, partly in section, of the rail anchor ofFIGS. 1 and 2, as it is formed on Ia jig with a section of a rail basesuperimposed thereon t-o illustrate the corresponding points of contact.

FlG. 4 is a side elevation, partly in section, showing the jig with therail anchor formed thereon, prior to curing of the anchor anddiagrammatically illustrating the strands of the reinforcing filaments.

FIG. 5 is a top plan view of the assembly as shown in FIG. 4 and furtherillustrating the formation of the reinforcing ilaments.

FIG. 6 is an end View of the structure shown in FIG. 4 pointing out theformation or' the filaments in the area of the curvilinear jaw portionof the anchor.

FIG. 7 is a vertical sectional view taken on the line '7-7 in FIG. 4,and illustrates a diierent type of jig assembly for the production of amodified or T-shaped plastic rail anchor.

Similar reference characters designate corresponding parts throughoutthe several figures of the drawing.

Referring now to the drawings, it will be understood that thecross-sectional shape may be varied from rectangular, channel, orT-shape, but for purposes of illustration, FIGURES l and 2 disclose arail anchor, generally designated A, of the tie-bearing type. The anchorof FIGURES 1 and 2 is provided with the usual curvilinear jaw or hook lattached at its lower portion to a base 2 which terminates at its freeend with a locking lug 3. FIGURE 2 shows the rail anchor as applied to arail R having a pair of base flanges 4 and 5. As is conventional, suchanchors which previously have been constructed of steel, may be appliedto the rail ibase by striking the outer periphery of the curvilinearresilient jaw gripping portion 1 with a tool such as a maul or the like.Also, the anchor may be applied by machines available on the market andwhich either strike the anchor as indicated above, or are pressed on bya iluid ram.

In the present instance, the anchor is provided with invention.

a transverse over-drive preventing abutment shoulder 6 so that whenapplying the anchor, said shoulder will strike the outside of the railange at the same time V.thatthe lug portion 3 snaps up over the outsideof the opposite rail-ange 4. The springing of the lug portion 3 aboutthe edge of the flange 4 is due to the inherent resiliency created bythe tensile strength incorporated in the jaw or hook ofthe anchor andcarried through to the ybase V2. This same tensile strength providesgripping *basic classifications; namely, thermoplasticand'thermosetting. Athermosetting resin is the desirable type ofmaterial for the present device in preference to the use of-thermoplastic resins, since the latter are long chain Y compounds whichsoften upon the application of heat.

As thermoplastic compounds undergo no chemical changes and can be heatedand cooled any number of times -without change, they find little 'use inmany structural applications, since they have limited resistance to heatand are subject to cold flow under load.

Accordingly, thermosetting resins are the most desirable compounds. Thebasic property of thermosetting resins is to change under heat bypolymerization to form infusable cross-linke-d compounds. Many of thesecompounds require heat to complete the reaction, but others,

for 'example the epoxies, are exothermic reactions and the heat ispurely an accelerator to increase the speed of the reaction and toincrease the permissable operating In view of their properties, thethermosetting epoxy resins Vare the most preferred compounds for use inproducing the present invention. Such compounds include theVepoxy-phenolics, epoxy-polyamides, epoxy-polysulphides,

etc.

Even though'the above resins appear to be the most suitable, numerousphenolic polyester, polycarbonate,

polyt'riflourethylene, silicon, and phenol silane compounds cannotbeignored; however, the present description will be confined to thediscussion of a rail anchor constructed 'of the epoxy type of syntheticresins.

In order to produce a rail anchor of plastic possessing the requiredstrength which is a most criticallyrequired p'roperty'between theopposed nose portion 7 and base contact point 8 of the jaw, it has beenfound necessary to'provideV suitable reinforcing means in combinationwith the plastic resin.

Applicants have found that the most desirable reinforcing can beprovided by utilizing a structural filler in the'nature of (glassstrands more commonly referred to as glass fibers or roving. Numerousglass fiber reinforced epoxy resin compounds are available fromcommercial chemical concerns which may be utilized in the presentusually referred to a glass iilled epoxies, are usually supplied onspools ready for use by the manufacturer. The most common use heretoforefor this product has been for use in filament winding by the electricalindustry and for pressure vessels, rocket cases, tubular and tank typestructures. Any suitable type of glass reinforcing strands or roving maybe used in combinationwith any of various compounds of lepoxy resins.For maximum strength, a

ratio by weight of approximately 70% glass roving to 30% epoxy resin isrecommended. Y

A typical lcomposition for the glass roving may be, for example: silicondioxide, 26 percent; aluminum oxide,

'64 perceiinmagnesium'oxide l0 percent. VSuch a com- These plasticimpregnated fibers or roving,V

ytemperature of the resultant anchor when put into service.

position provides a low alkali magnesia alumina silicate glass ofextremely high tensile strength. When combined with any selected epoxyresins, this glass filled epoxy has been tested to indicate a tensilestrength on the order of 450,000 p.s.i. The above described glass filleris merely an example of one composition which may be employed incarrying out the present invention as numerous other rovings may also beused composed of high strength specialty glass, high modulus glass, orquartz fibers.

Mechanical damage is the sole factor having any significant effect onthe strength of a glass fiber reinforced plastic rail anchor, while onthe other hand a steel rail anchor is also affected by time, staticload, cold flow, exposure to the elements, annealing, stress corrosionand cracking, and crack propagation. In order to utilize to a maximumadvantage, the inherent strength of a glass fiber reinforced epoxy resinin connection with the formation of a rail anchor, applicants havedevised a novel method whereby the epoxy resin impregnated roving Visarranged in a particular manner prior to curing to prothe base 12. ofthe jig is shaped'such that its perimeter corresponds generally to thedesired inner perimeter of the rail anchor A.

As will be noted from this figure wherein the base of rail R issuperimposed, one end V135 of the jig corresponds in position to theedgeof the base flange 4, while the opposite end 14 of the jig isshapedto conform to the inner surface of the rail anchor jaw andcorresponds at one point tothe end of the rail flange 5. Thiscorresponding point is the point at which the abutment shoulder 6 isdesigned to strike the edge of the base flange 5. Similarly, thedistance between the surface 1S on the bottom of the jig and opposedsurface 16 on the top thereof is less than the corresponding distancebetween the similar points on the railflange 5 as clearly shown in FG.3. This is to ensure that the space forming the resilient griping jawopening of a completed rail anchor will be slightly less than thecorresponding thickness of the rail flange at thisV same point so thatthe jaw of the anchor will be slightly expanded or spread apart as theanchor is urged onto a rail base. This is a feature which would beobvious in order to produce the required gripping of the jaw upon therail base to prevent displacement of the anchor when in position.

The jig 11 may be formed'of any suitable material Y which isself-sustaining and not affected by the application of ytemperatures inthe range of 300-500 F. The jig is providedwith two bores 17 and 18passing from the top through the bottom thereof. Adapted to be removablydisposed inthe bones17V and 18 are a pair of winding pins generallydesignated 19 and 20, respectively, each pin projecting from both sidesof the jig a substantial distance when inserted therethrough to provideupper sections 19a, 25m and lower sections 19b, 20h. The pin 19,adjacent the jaw-forming end of the jig, is disposed substantiallynormal to the longitudinal axis of the jig whilethe pin 26 is angularlydisposed through the jig, so that its lower section 20h projectsdownwardly and outwardly from the jig. v

In the formation of a rail anchor according to the present invention,glass-filled epoxy resin strand material is wound around the pins 19 andZG'Yin such a manner that the individual strands 21, or roving material,when assembled and cured, form a completed article having maximumtensile strength in the two most desired areas of the anchor, namely, ata point beneath the web W of the rail and most particularly, in the areaof the -jaw or hook portion 1. To obtain the particular arrangement ofthe wound strands 21, any of suitable winding machines may be utilized.Such machines are well known for use in electrical iilament winding,motor winding, and armature winding, and may be programmed by means cisuitable cams, etc., so that an article such as the shape ot the subjectanchor may be formed by automatic means. Whatever means are used to windthe strands Z1 upon the jig is immaterial so long as the proper patternis achieved, as set forth hereinafter. Before winding the glass-lledepoxy resin strand on the jig 11, the various exposed surfaces of thejig and pins 1h and 2.0 are coated with a suitable parting composition,such as any one of the well known silicone compounds so that the railanchor, after it is formed and cured, may be readily removed from thejig after the pins 19 and Ztl are withdrawn.

In forming the anchor upon the jig, the free end of the epoxy roving orstrand 21 is suitably anchored to the jig, for example, by looping aboutthe lower section Zlib of the pin 2t? adjacent the jig body. Thereafter,the continuous strand 21 of the material is wound in a ligure 8 patternstarting at pin section Zlib, crossing at a point on the bottom of thejig intermediate the pin sections 1917 and 2Gb, passing around the lowersection 1% of pin 19, and again crossing at what will be the medialportion of the jaw 1 before passing around the uper section 19a of thepin 19. During the return winding of the strand 21, it will be seen thatit will traverse a course opposite to that of the strand as it proceededpreviously from pin 20 to pin 19. In this manner, it will be seen thatthe strands cross one another during each passage of the strand from pin19 to pin 2d at the point 22 in the medial portion of the jaw 1 andagain at the point 23 substantialy intermediate the pin sections 19h and2Gb.

In order to contain the windings formed by the multiplicity of strands21, subsequently applied to the jig, suitable side plates 2d and 25 areattached to the sides of jig 11 by any suitable means providing forquick attachment and release therefrom. lt will be understood that thesides plates 24 and 25 extend vertically at least a distance as great asthe vertical height of the rail anchor and likewise extend horizontallya distance corresponding to the overall length of the anchor. In thisWay, all of the strands 21 will be contained within the limits of theside plates 24 and 25 while the width of the jig 11 is obviouslypredetermined depending upon the desired width of the finished anchor A.One of the principal advantages afforded by the side plates 24 and 25 isthat after curing, when the individual impregnated strands 21 will ha 'econsolidated, the iinished anchor will have substantially vertical sidewalls, which feature is most desirable in the utilization of the anchorsince the side walls form the bearing contact surface against thecross-tie T and any irregular curvature of an achor side wall would notprovide a positive abutment for anchoring of the rail to the tie throughthe anchor.

After a sufcient number of windings of the strand material have beenmade on the jig according to the desired size of anchor, the jigassembly is cured by heating. Many of the thermoplastic resins may becured by means of a single heat, while others may require a postcure inorder to achieve maximum physical properties.

An exemplary cure cycle which may be used in the forma- 6 tion of thepresent rail anchor when produced with epoxy resin designated EF 787, asproduced by U.S. Polymeric Chemicals, Inc., is as follows:

Cure cycle: 1 hour at 18W-200" F. Post cure: l hour at 250-300 F.

After the appropriate curing has been achieved and the anchor removedfrom the jig, it Iis ready for immediate use, although some epoxy resinsmay increase in strength for about 2l days after curing and thereforeshould be stored for this period.

Referring now particularly to FIG. 7, it will be seen that the sideplates 24 and 25 may be furnished with additional forming blocks 26 and27, respectively, which blocks are removably attached to the innersurface of the walls 24 and 25 for the purpose of deiining a T-shapedarea completely surrounding the jig in the area to be occupied by ananchor. In this manner, a plastic rail anchor may be produced of the tieplate and cross-tie bearing type generally corresponding in shape to arail anchor such as that set forth in Patent No. 2,719,008 datedSeptember 27, 1955, to Ruppert.

In forming a plastic rail anchor having a T-shaped cross section, aplurality of windings are made around the jig between the pins aspreviously described herein until the area 28 between the blocks 26 and27 and the jig 11 is lled with the strand material. At this point the removable blocks 26 and 27 are added since it would have been most diicultto wind the :strands in the area Z8 if said blocks were permanentlyattached to the side plates 24 and After attaching the blocks 26 and 27,the winding is continued until the area 29 between the blocks is filledto the proper dimension after which the woven strands are curedsimilarly to the manner described previously.

We claim:

1. A rail anchor comprising, a molded body of reinforcing strandsimpregnated with a thermosetting plastic resin, said body including asubstantially longitudinally extending base and a nose portion disposedin a plane vertically spaced above said base, a curvilinear jawconnecting said base and nose portion, and said strands in said bodydeposited in crossing relationship at the medial portion of said jaw.

2. A rail anchor according to claim 1, wherein, said strands are ofglass composition.

3. A rail anchor according to claim 1, wherein, said thermosettingplastic resin is of the epoxy class.

4. A rail anchor according to claim 1, wherein, said strands also crossat a point substantially medially of said base.

5. A rail anchor according to claim l, wherein, said body issubstantially of rectangular cross section.

6. A rail anchor according to claim 1, wherein, said body is of T-shapedcross section.

References Cited by the Examiner UNITED STATES PATENTS 1,559,589 11/25wan ass-330 2,719,008 9/55 Ruppert 23S-327 2,977,268 3/61 Randolph 264-257 3,056,167 10/62 Knoppei 156-500 X 3,058,165 10/62 Purvis 264-257 LEOQUACKENBUSH, Primary Examiner.

ARTHUR L. LA POINT, Examiner.

